/*
 * Copyright 2002-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.servlet.view;

/**
 * Abstract base class for template view resolvers, in particular for FreeMarker views.
 *
 * <p>Provides a convenient way to specify {@link AbstractTemplateView}'s exposure
 * flags for request attributes, session attributes, and Spring's macro helpers.
 *
 * @author Juergen Hoeller
 * @see AbstractTemplateView
 * @see org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver
 * @since 1.1
 */
public class AbstractTemplateViewResolver extends UrlBasedViewResolver {

    private boolean exposeRequestAttributes = false;

    private boolean allowRequestOverride = false;

    private boolean exposeSessionAttributes = false;

    private boolean allowSessionOverride = false;

    private boolean exposeSpringMacroHelpers = true;


    @Override
    protected Class<?> requiredViewClass() {
        return AbstractTemplateView.class;
    }

    /**
     * Set whether all request attributes should be added to the
     * model prior to merging with the template. Default is "false".
     *
     * @see AbstractTemplateView#setExposeRequestAttributes
     */
    public void setExposeRequestAttributes(boolean exposeRequestAttributes) {
        this.exposeRequestAttributes = exposeRequestAttributes;
    }

    /**
     * Set whether HttpServletRequest attributes are allowed to override (hide)
     * controller generated model attributes of the same name. Default is "false",
     * which causes an exception to be thrown if request attributes of the same
     * name as model attributes are found.
     *
     * @see AbstractTemplateView#setAllowRequestOverride
     */
    public void setAllowRequestOverride(boolean allowRequestOverride) {
        this.allowRequestOverride = allowRequestOverride;
    }

    /**
     * Set whether all HttpSession attributes should be added to the
     * model prior to merging with the template. Default is "false".
     *
     * @see AbstractTemplateView#setExposeSessionAttributes
     */
    public void setExposeSessionAttributes(boolean exposeSessionAttributes) {
        this.exposeSessionAttributes = exposeSessionAttributes;
    }

    /**
     * Set whether HttpSession attributes are allowed to override (hide)
     * controller generated model attributes of the same name. Default is "false",
     * which causes an exception to be thrown if session attributes of the same
     * name as model attributes are found.
     *
     * @see AbstractTemplateView#setAllowSessionOverride
     */
    public void setAllowSessionOverride(boolean allowSessionOverride) {
        this.allowSessionOverride = allowSessionOverride;
    }

    /**
     * Set whether to expose a RequestContext for use by Spring's macro library,
     * under the name "springMacroRequestContext". Default is "true".
     *
     * @see AbstractTemplateView#setExposeSpringMacroHelpers
     */
    public void setExposeSpringMacroHelpers(boolean exposeSpringMacroHelpers) {
        this.exposeSpringMacroHelpers = exposeSpringMacroHelpers;
    }


    @Override
    protected AbstractUrlBasedView buildView(String viewName) throws Exception {
        AbstractTemplateView view = (AbstractTemplateView) super.buildView(viewName);
        view.setExposeRequestAttributes(this.exposeRequestAttributes);
        view.setAllowRequestOverride(this.allowRequestOverride);
        view.setExposeSessionAttributes(this.exposeSessionAttributes);
        view.setAllowSessionOverride(this.allowSessionOverride);
        view.setExposeSpringMacroHelpers(this.exposeSpringMacroHelpers);
        return view;
    }

}
